GB1598558A - Method and apparatus for producing slubby yarn - Google Patents

Description

PATENTS ACT 1949 SPECIFICATION NO 1598558 The following corrections were allowed under Section 76 on 28 July 1982.

Page 2, line 22, after means (second occurrence) insert.

Page 4, line 54, after pattern delete illustrated in insert.

Page 4, line 55, delete Figure 18.

Page 5, line 39, after configuration delete of Figure 18. insert.

Page 5, line 44, for (517, 050 pascal) read (517, 106 pascal) Page 6, line 37, after ranges delete between insert from Page 6, line 48, after diameter delete between insert from Attention is also directed to the following printers errors : Page I, line 40, for loosing read losing Page 2, line 12, for pluraity read plurality Page 3, line 64, for provodes read provides Page 4, line 53, for in read inch Page 5, line 36, for whee read wheel = Page 6, line 34, for caried read varied Page 7, line 19, for and read or Page 8, line 3, for to read or THE PATENT OFFICE 16 August 1982 Bas 91835/7 (54) METHOD AND APPARATUS FOR PRODUCING SLUBBY YARN (71) We, PPG INDUSTRIES, INC. a corporation organized and existing under the laws of the State of Pennsylvania, United States of America, of One Gateway Center, Pittsburgh, State of Pennsylvania 15222, United States of America, (Assignees of HERBERT WILLIAM BARCH, AUGUST GEORGE BOHY, WARREN WENDELL DRUMMOND and ALAN THOMAS McDONALD), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement : The present invention relates to an apparatus and method for producing slubby yarn.

Novel yarns or strands are produced by a variety of processes in the textile field and find utility for many specific textile purposes, for example, in the manufacture of draperies or industrial cloths used as reinforcement for resin articles. Yarn, as referred to in this specification, includes for example twisted yarns, untwisted strands and rovings of strands.

Many processes have been designed, especially in processing glass fiber strands, to produce decorative effects on textile strands to render them useful in providing bulk for cloth to be woven for decorative purposes as well as cloth woven for industrial purposes e. g. resin reinforcement.

Thus, in U. S. Patent No. 3, 388, 444 a process is described in which glass fiber strands are passed through a texturizing jet at various rates of speed and air under pressure is introduced into the jet to entangle the yarns passing therethrough to produce a bulking effect on the yarn issuing from the jet. In another process, bulky textile yarn is produced by providing a core and effect yarn, each of which travels at different speeds as they are passed through an air jet device to filamentize the fibers of the faster travelling strands and entangle them within the core yarn. A typical process of this type is illustrated in U. S.

Patent No. 3, 262, 177. Another process for producing a bulky yarn having intermittent bulking along its length is shown in U. S. Patent No. 3, 410, 077.

Whife all of the above processes are useful in producing novel textile strands, a need still exists in the art for a process which will produce efficiently a slubby textile strand in which slubs of good integrity are present. Minimized filament damage caused by breaking filaments during the processing of a strand is also a desired goal in producing slubby strands. Filament damage to strands using the procedures of the prior art often reduces strand strength below an acceptable value. Further, in producing textue strands having slubs thereon, it is a desired goal to produce slubs randomly so that the cloth woven therefrom does not develop a fixed pattern.

By means of the present invention it is possible to produce at high speed a textile strand having slubs, which may be random or intermittent, along the length thereof. The slubs have extremely good integrity in that, once provided on the textile strand, they cannot easily be pulled out of the strand by pulling the strand at either end of the slub. This feature is important in that the strands provided in accordance with the present invention can be woven and otherwise physically handled in various textile finishing operations when they are utilized to produce cloth without loosing slub integrity. When glass fibers are used as the textile strand, it has been found that the processes can produce a slubby strand having very few filament breaks therein. In addition, slubs of varying size can be produced on the same strand and in random locations. By varying yarn tension, it is also possible using the processes and apparatus herein described to produce texturized yarns. Novel apparatus for producing slubs along a textile strand are also provided which are simple in construction and permit considerable versatility in the production in slubs as to their size and their location along a given length of a continuous strand.

The strand produced by the present process is characteristically twisted on either end of the slubs produced in accordance with the practice-of the present invention and this greatly assists in locking the slubs in place so that they cannot be inadvertently removed by subsequent tension placed on either end of a slub during processing of the strands on which they are psotioned. It has also been observed that strands produced in accordance with this invention, especially those produced from glass fiber strands, have little or no fiber breaks therein, thus producing a slubby glass fiber strand having extremely high tensile strength.

According to the present invention there is provided a method of preparing a slubby strand of fibers, which comprises passing a consolidated textile strand containing a plurality of fibres therein over a surface containing a pluraity of fluid passages over which the textile strand passes, impinging fluid, under pressure, on the surface of the textile strand and exhausting a portion ouf the fluid so introduced through said fluid passages, and removing the textile strand, having slubs thereon from said surface containing the passages.

The invention includes apparatus for producing a slubby strand of fiber, which comprises, in combination, means to receive a consolidated textile strand, said means comprising a surface, means to draw the consolidated textile strand from the surface, a plurality of fluid passages on said surface, exhaust means for the fluid passages positioned below said surface, and means to impinge fluid, under pressure, on the surface of the strand while the strand is being drawn over said surface containing the passages. The invention may also include means to adjust the volume of exhaust from each of the fluid passage exhaust means Thus, in accordance with the present invention a consolidated textile strand containing a plurality of fibers therein is passed over a surface which includes a plurality of fluid passages over which the strand passes during its travel to a collecting zone. Fluid under pressure, e. g. air, impinges on the surface of the strand. As the fluid, e. g. at a pressure of from 20 to 80 psig (137, 895 to 551, 580 pascal), passes through the strand, the fluid twists and bulks the strand along its length. As the surface has been provided with fluid passages, part of the fluid is exhausted through those fluid passages after passing through the strand. The bulked strand is removed from the surface provided with the passages thereby producing a slub at various points on the strand and the strand with the slubs thereon may be transported to a collection zone where it is wound or collected in any suitable manner for ultimate distribution to the customer. By varying the rate of exhaust in one or more of the fluid passages, varying the speed of travel of the strand over the surface containing the passages, or varying the pressure of the fluid, variations in slub size for a given strand can be readily realized.

The present invention will now be further described by reference to the accompanying drawings, in which : Figure 1 shows a schematic diagram of the operation of one embodiment of the present invention using conventional forming packages as the feed and wherein two glass strands are being consolidated into a single strand during their passage over the strand treating surface ; Figure 2 is an enlarged view of the wheel 13 of Figure 1, partially broken away, to show the orientation of the fluid passages and the exhaust holes therein ;-.

Figure 3 is a cross-section of a fluid passage located on the-surface of the whee) 15 of Figure 2 ; Figure 4 is an artist's rendition of a photograph of a glass strand produced in accordance with the embodiment of Figure 1 of the present invention ; and Figure 5 shows a schematic diagram of the embodiment of Figure 1 of the present invention used to produce a slubby strand from a single strand removed from a bobbin.

In the production of slubs on textile strands in accordance with the practice of the present invention, any conventional textile strand can be employed, provided it is capable of being opened up by the passage therethrough of fluid under pressure, e. g., air, steam, water, nitrogen or carbon dioxide. Preferably, gaseous fluids are employed and most preferably air is employed as the gaseous fluid. The invention has particular utility in the production of slubs on consolidated strands containing a plurality of glass fibers and can produce these slubs with little or no breakage of the fibers during the formation thereof. This is an important consideration in the preparation of glass strands because glass filaments, in general, have little or no elasticity and often the prior art processes involving the bulking of glass strands produce strands which may have many broken filaments therein.

For convenience in the discussion of the present process, the process will be described with reference to the production of glass strands having slubs placed along their length, although it will be understood that the invention is applicable to the production of slubs on any synthetic or natural textile strand containing a plurality of filaments in the strand, e. g., nvlon. potvester. acetate, or cotton.

In the production of slubby glass fiber textile strands, the source of the strand can be varied. Thus, for example, by recourse to special processing techniques, glass fiber strands can be processed in accordance with this invention using as the strand source a forming package, i. e. wound strand on a tube produced by winding as the glass fiber strand is prepared from a molten source of glass. Fuming packages can be employed either wet or dry. The glass fiber strands may also be processed directly from bobbins which are normally produced by placing a forming package on a conventional twist frame and twisting the strand to any desired twist value as it is removed from the forming packages and wound on the bobbin. In addition, the strands may be slubbed directly as they are formed from a bushing.

It is also contemplated, utilizing the present invention, to apply the slubs to the glass fiber strand on a conventional textile twist frame by feeding the strand contained on forming packages through the slubbing operation of the present invention prior to collecting them on the bobbins of the twist frame. While in the specific embodiment of the invention shown in Figure 1 two glass fiber strands are utilized to produce the final strand product, it will be readily understood that more than two strands can be fed to the system and slubbed in the same manner as the two strands depicted in Figure 1 to produce a final slubbed strand.

Obviously, it is also contemplated that a single strand feed be employed to produce yarns in accordance with the invention. Thus, while Figure 5 shows a single end strand being slubbed from either a bobbin or a forming package source, it will be understood that multiple end products may be produced by combining several strands prior to subjecting them to slub treatment in these embodiments.

For convenience, the invention will now be described with reference to the accompanying drawings and utilizing as the exemplary textile strand one composed of a plurality of glass fiber filaments.

Turning to Figure 1, there are shown therein, positioned in a side-by-side relationship, two glass strand containing forming packages 1 and 2. Each of these forming packages 1 and 2 have inserted therein a central pin 6 and 5, respectively, which contains on its outer surface a circular ring member 7 and 8, respectively. These ring members 7 and 8 are provided so that the strand can be ballooned out over the forming package for easy removal. The strands 3 and 4, removed from the packages 1 and 2, respectively are consolidated into a single strand in an eyelet 9 and passed through an eyelet 10 for feeding to a rotating wheel 13. Located on the surface 21 formed on the face of the wheel 13 are a plurality of gas passages 14 which are drilled into the body of the wheel member 13. These passages 14 are better shown in Figure 3. The surface 21 may be a curved, generally U-shaped, surface, as shown, or may be a relatively flat surface. Jet 12 provides the gas for effecting the twisting and slubbing process. Gas passages 14 communicate with the atmosphere surroundmg the wheel member 13 through a plurality of holes contained on a circular plate member 15 affixed to the surface of the wheel member 13. The holes, 23, 24, 25, 26, 27, 28, 29 and 30 shown in Figure 2 on the plate member 15 are exit holes of varying diameter which are placed over the opening of the gas passages 14 and vent the passage 14 to the atmosphere. By adjusting the position of circular plate 15, any of the holes 23 to 30 can be aligned with the passagel4. If desired, the plate 15 can be placed over any of the passages so as to close the passage from the atmosphere. Thus, as will be readily appreciated, the venting of the gas passages 14 to the atmosphere canut-bue readily controlled.

Adjustment of the venting provides a varying gas flow through the passage 14. The strand passes from wheel 13 through eyelet 11 to a winding mechanism 19.

As shown in Figure 4, the invention produces a slub 16 on strand 17. The slub 16 is characterized by being interposed between counterdirectionally twisted strand on either side thereof thus rendering the slub physically stable during later processing. It is also characteristic of the slub 16 produced in accordance with this invention that very few breaks occur on the strands. This is particularly useful in the production of glass fiber strands, since, due to their lack of elasticity, most texturising systems utilized in the production of glass fiber strands result in numerous breaks of filaments and a consequent significant reduction in the tensile strength of the strand produced.

In an alternative method of producing strand containing slubs in accordance with the present invention and with particular reference to Figure 5, a single end 38 is utilized to produce glass fiber strand having intermittent slubs 39 produced along the length thereof.

In this embodiment, the single strand 38 is removed from a bobbin 34, passed through eyelet 35 and through tension control members 36 and 37. The tension control members are typically polished plates 36 and 37 through which the strand 38 is passed. The tension is normally controlled by varying the weight of the top plate 36. or by placing more than one plate 36 over the plate 37. The strand is then passed through eyelet 10 and over the wheel member 13 which is identical to the wheel of Figures 1, 2 and 3. Jet 12 provodes the gas for effecting the twisting and slubbing process. Appropriate adjustments are made in the wheel

member 13 to place over the apertures of the gas passages 14 located in the sidewall of the wheel 13 the appropriate hole sizes. This is accomplished by rotating the plate 15 to line up the appropriate hole therein with the exit of passage 14. In this manner, slubs 39 are produced from a single strand 38 in the same manner as they are produced on the double strand shown in Figure 1 and the strand passes from wheel 13 through eyelet 11 to a winding mechanism 19. The strand produced characteristically is counterdirectionally twisted on either end of the slub 39 thus produced.

The exact mechanism which results in the formation of the stubs in the vnrn trestefi in TABLE I Break Strength Run Yarn Designationt ~ Slubbed (Pounds) Kilograms 1 DE-75 1/0 1. OZ No 3. 34 1. 5 2 DE-37 1/0 1. OZ No 13. 66 6. 19 3 DE-75 1/0 1. OZ (2 ends) No 14. 02 6. 35 4 DE-37 1/0 1. OZ (2 ends) No 26. 24 11. 89 5 DE-75 1/0 1. OZ Yes 3. 88 1. 75 6 DE-37 1/0 1. OZ Yes 9. 98 4. 52 7 DE-75 1/0 1. OZ (2 ends) Yes 10. 67 4. 83 8 DE-37 1/0 1. OZ (2 ends) Yes 22. 02 9. 98 *The lettering DE refers to the filament diameter, the DE fiber having a diameter of . 00025 inch (0. 0063 millimeter). The number immediately following the letter designation times 100 equals the number of yards of yarn per pound (0. 45 kilogram) of glass. The designation 1/0 indicates the number of ends utilized in the yarn, 1/0 being one end. The designation 1. OZ indicates one twist in the Z direction.

Example II In another run a glass strand was slubbed using a high speed winding system such as is shown in U. S. Patent No. 3, 730, 137. The only modification of that system made was that the jets were removed and the size normally applied before winding was not applied. In that system a DE-75 glass strand was passed over a 3 inch (76. 2 millimeter) diameter wheel surface. The surface of the wheel had 3/16 inch (4. 76 millimeter) diameter holes drilled in it and vented to the atmosphere through the side wall of the whee. Each vent hole on the wheel side wall was 1/16 inch (1. 58 millimeter) in diameter. Air was fed to the surface of the strand as it passed over the wheel surface at 75 pounds per square inch gauge (517, 106 pascal). The air was fed through a nozzle having the"dog bone"configuration of Figure 18.

The winder used wound the strand at 3, 000 feet (914. 4 meters) per minute. The strand was thus removed from a bobbin passed through an eyelet and conventional tensioning discs and over the wheel. The 3/16 inch (4. 76 millimeter) holes on the wheel were spaced 3/8 inch (9. 52 millimeters) from each other. The air was turned on at 75 pounds per square inch gauge (517, 050 pascal) and the strand wound on a standard Leesona. winder at 3, 000 feet (91X. 4 meters) per minute. The resulting spool of yarn hald considerable texture and slubs formed along its length.

Example 111 Using the same equipment as Example II, a similar run was made with a DE-75 glass strand run from a bobbin source. This run was made at a winding speed of 1, 100 feet (335. 28 meters) per minute and using the air at 50 pounds per square inch guage (344, 737 pascal). Good slub formation was achieved and the strand appeared to have excellent strength.

Example IV The run of Example II was repeated with a DE-75 glass strand using a 3, 000 feet (914. 4 meter) per minute winding speed and 75 pounds per square inch gauge (517, 106 pascal) air and an after size was applied to the strand after it passed over the wheel surface and before it was taken up by the winder in the manner shown in U. S. Patent No. 3, 370, 137. The resulting strand contained slubs and texture and appeared to have excellent strength.

Example V A run similar to Example IV was made using a DE-75 glass strand with a size applied after the strand passed over the wheel and before it was collected. The winding speed was 1, 100 feet (335. 28 meters) per minute and theXir pressure used was 50 pounds per square inch gauge (344, 737 pascal). A good slub containing strand having good strength characteristics was produced.

Example VI In another operation, a wet forming package operation is simulated by applying moisture to a plurality of bobbins and utilizing wet bobbins as the source of supply of glass fiber yarn to the wheel surface 13. In this instance, the wet strands 3 and 4 are consolidated through an eyelet 9, passed through eyelet 10 and run on the concave surface of wheel 13 and across the air passages 14 associated therewith. High pressure air at 40 pounds per square inch gauge (275, 790 pascal) is fed onto the strand through jet inlet 12 as the strand passes over the wheel surface and the holes are adjusted at the vents of each of the gas passages 14 to provide a 3/16 inch (4. 76 millimeter) diameter exit. Each of the holes 14 drilled in the wheel surface has a diameter of 3/16 inch (4. 76 millimeters). The resulting yarn is wound at 1, 340 linear feet (408. 4 meters) per minute and contains slubs 16 positioned on the finished strand which characteristically are similar to that shown in Figure 4, that is, the strand is twisted on either end of the slub and the slub is uniform and shaped as shown in Figure 4 of the drawings.

Considerable versatility is provided by the present method and apparatus in that strand effect can be changed considerably with small changes in the system. Thus, at lower speeds, 300 to 1, 000 feet (91. 44 to 304. 8 meters) per minute and air pressures in the 30 to 75 pounds per square inch gauge (206, 842 to 517, 106 pascal), the slubs produced on a strand tend to be more clearly defined with little strand disturbance in between slubs. At similar air pressures and higher speeds, over 1, 000 feet (304. 8 meters) per minute, the effect on the strand is to provide for more texturing of the strand between slubs. While a wheel surface was employed in the Examples, it is also feasible to use a stationary plate which may have appropriate fluid passages therein or a moving belt which may be provided with suitable apertures therein. Similarly, while steady air feeds are employed in the Examples, it has been found that intermittent air flow can be used as a means to provide intermittent slub formation on a given length of strand with relative ease.

In general, the speed of strand travel can be caried from 200 to 5, 000 feet (60. 96 to 1, 524 meters) per minute or more, with speeds of 300 to 3, 000 feet (91. 44 to 914. 4 meters) per minute being those typically used. Air pressure, where air is used as the fluid, generally ranges between 20 to 80 pounds per square inch gauge (137, 895 to 551, 580 pascal), with pressures of 30 to 75 pounds per square inch gauge (206, 842 to 517, 106 pascal) being typical of those emploved. those employed.

Where a wheel surface is employed as the working surface on which the fluid is forced through the strand to produce the slubby effect, the surface may move at the speed of the strand or slightly in excess thereof. The process will still operate with the surface in a stationary position.

The hole diameter and spacing of the holes when employed to fluff the strands on the working surface can be varied considerably to produce variousieffects. Tfus, while a hole of 0. 187 inch (4. 76 millimeters) in diameter has been described in the above Examples as desired in producing slubs on a glass strand, this can be varied considerably. Thus, holes ranging in diameter between. 06 to. 5 inch (1. 524 to 12. 7 millimeter's) can be readily employed. In like fashion if desired, vent holes can be adjusted to sizes other than the. 06 inch (1. 524 millimeter) diameter employed in the Examples.

Claims (34)

WHAT WE CLAIM IS :

1. A method of preparing a slubby strand of fibers, which comprises passing a consolidated textile strand containing a plurality of fibres therein over a surface containing a plurality of fluid passages over which the textile strand passes, impinging fluid, under pressure, on the surface of the textile strand and exhausting a portion of the fluid so introduced through said fluid passages, and removing the textile strand, having slubs thereon, from said surface containing the passages.

2. A method as claimed in claim 1, wherein the fluid is impinged at a pressure of from 20 to 80 psig (137, 895 to 551580 pascal) on the surface of the strand.

3. A method as claimed in claim 1 or claim 2, wherein the strand is removed from the surface containing the passages at a speed of 200 to 5, 000 feet (60. 96 to 1, 524 meters) per minute.

4. A method as claimed in any one of claims 1 to 3, wherein the surface containing the passages is rotating.

5. A method as claimed in any one of claims 1 to 4, wherein the fluid passages through which the fluid is exhausted are controlled to vary the volume of fluid exhausted through each passage.

6. A method as claimed in claim 4, wherein the exhaust fluid volume is controlled as desired in one or more of the passages to thereby control the size of the slubs produced while the flow of fluid introduced onto the surface containing the passages and the speed of rotation of the surface containing the passages are maintained constant.

7. A method as claimed in claim 4, wherein the exhaust fluid passages are maintained equal in volume and the flow of fluid onto the surface of the strand is varied during passage of the strand over the rotating surface containing the passages while the surface containing the passages is rotated at a constant speed.

8. A method as claimed in claim 4, wherein the rotating surface containing the passages is subjected to varying rates of speed during passage of the strand over the surface containing the passages.

9. A method as claimed in any of claims 1 to 3, wherein the strand is passed over the surface containing the passages, the fluid is impinged on the surface of the strand continuously, and the strand is twisted and bulked by the fluid.

10. A method as claimed in claim 9, wherein the surface containing the passages is formed on the periphery of a wheel and said wheel is rotating.

11. A method as claimed in claim 9 and claim 10, wherein the strand passing over the surface containing the passages is varied in its rate of speed.

12. A method as claimed in claim 2, wherein the consolidated textile strand is a glass fiber strand and the strand is passed over the surface containing the passages at a speed of 200 to 5, 000 feet (60. 96 to 1, 524 meters) per minute.

13. A method as claimed in claim 12, wherein the fluid passages are from 0. 06 to 0. 5 inch (1. 524 to 12. 7 millimeter) in diameter.

14. A method as claimed in claim 2, wherein the consolidated textile strand is a glass fiber strand, the strand is passed over the surface containing the passages at a speed of 200 to 5, 000 feet (60. 96 to 1, 524 meters) per minute, and the strand is twisted and bulked by the fluid.

15. A method as claimed in any of claims 12 to 14, wherein the fluid is air, the strand is passed over the surface containing the passages at a speed of 300 to 3, 000 feet (91. 44 to 914. 4 meters) per minute, and the air pressure employed is from 30 to 75 psig (206, 842 to 517, 160 pascals).

16. A method as claimed in any of claims 12 to 15, wherein the fluid is impinged on the surface of the strand intermittently.

17. A method as claimed in any of claims 12 to 15, wherein the fluid is impinged on the strand continuously and the speed of the strand is varied between said speeds during formation of the slubby strand.

18. A method as claimed in any of claims 1 to 3, wherein the consolidated textile strand is a consolidated glass strand prepared by drawing a plurality of glass filaments from a molten glass source, coating the filaments with a suitable binder or size and consolidating into a strand, and the fluid is impinged on the surface of the strand as it passes over one or more of the fluid passages to thoroughly bulk the strand as the fluid passes through the strand into the fluid passages.

19. A method as claimed in claim 18, wherein the fluid is air and is impinged on the surface of the strand intermittently.

20. A method as claimed in claim 18 or claim 19, wherein the fluid passages over which the strand passes are not all equal in diameter.

21. A method as claimed in any of claims 1 to 3, wherein the consolidated textile strand is a consolidated glass strand prepared by drawing a plurality of glass filaments from a molten glass source, coating the glass filaments with a suitable binder or size and consolidating into a strand, and the fluid is impinged on the surface of the strand to intermittently twist and bulk the strand as the fluid passes through the strand.

22. A method as claimed in claim 21, wherein the surface containing the passages is formed on the periphery of a wheel and said wheel is rotating.

23. A method as claimed in any of claims 18 to 22, wherein the surface containing the passages is moving with the strand.

24. A method as claimed in any of claims 18 to 23, wherein the strand passing over the surface containing the passages is varied in its rate of speed.

25. An apparatus for producing a slubby strand of fiber, which comprises, in combination, means to receive a consolidated textile strand, said means comprising a surface, means to draw the consolidated textile strand from said surface, a plurality of fluid passages on said surface, exhaust means for the fluid passages positioned below said surface, and means to impinge fluid, under pressure, on the surface of the strand while the strand is being drawn over said surface containing the passages.

26. An apparatus as claimed in claim 25 further comprising means to adjust the volume of exhaust from each of the fluid passage exhaust means.

27. An apparatus as claimed in claim 25 to 26, wherein said surface containing the passages is formed on the periphery of a wheel and the fluid passages rotate with the wheel.

28. An apparatus as claimed in claim 27, wherein the fluid passages on the peripheral surface of the wheel pass into the body of the wheel and are vented on the sidewall thereof.

29. An apparatus as claimed in claim 28, wherein a movable plate having vent openings of differing diameters is placed over each fluid passage vent on the sidewall of the wheel.

30. An apparatus as claimed in any of claims 25 to 29, wherein the means to draw the consolidated textile strand over said surface is adapted to draw the strand over said surface at a speed of from 200 to 5, 000 feet (60. 96 to 1, 524 meters) per minute.

31. A method of preparing a slubby strand as claimed in claim 1 and substantially as hereinbefore described with reference to any of the Examples.

32. A method of preparing a slubby strand as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.

33. An apparatus for preparing a slubby strand as claimed in claim 25 and substantially as hereinbefore described with reference to any of the Examples.

34. An apparatus for preparing a slubby strand as claimed in claim 25 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.